Confederacy or confederate may refer to:
- Confederate state or confederation, a union of sovereign groups or communities
- Confederate States of America, a confederation of secessionist American states that existed between 1861 and 1865
- Confederate Ireland, a period of Irish self-government during the Eleven Years' War
- Canadian Confederation, the 1867 union of three British provinces (United Canada, split into Ontario and Quebec; Nova Scotia, and New Brunswick) as "one dominion under the name of Canada." Today, there are 10 provinces and three territories, and Canada (since 1982) is no longer a dominion.
- Confederation of the Rhine, a group of French client states that existed during the Napoleonic Wars
- Catalan-Aragonese Confederation, a group of Spanish states that were governed by one king
- Gaya confederacy, an ancient grouping of territorial polities in southern Korea
- German Confederation, an association of German-speaking states prior to German Unification
- Iroquois Confederacy, group of united Native American nations in present-day Canada and the United States
- Maratha Confederacy, a group of Indian states in the 1700s
- Muscogee Confederacy, Native American nation in Southern United States
- North German Confederation, a federation in northern Germany from 1867 to 1870
- Peru–Bolivian Confederation, a federation of several states in present day Peru and Bolivia that existed between 1836 and 1839
- Powhatan Confederacy, a group of Native American tribes on the Atlantic coast governed by a single chief
- Sikh Confederacy, a group of states confederated during the 18th century in the Punjab region
- Swiss Confederation or Switzerland, a federal republic in Europe
- Three Confederate States of Gojoseon, states thought to have existed in present day Korea during the Bronze Age
- Northwestern Confederacy, a group of Native American tribes in the Great Lakes region that united after the American revolution